Thiem has been injured since June and has not been able to participate in either Wimbledon or the Olympics.
In a video on Instagram, the Austrian says that he had a setback in training last week.
- I hope to be back in full form at the beginning of next season, he says.
- I work hard to meet all of you (the supporters) again where I belong, on the tennis court.
The World Six is the reigning champion of the US Open, which begins on August 30.